Enjoyment of online music, in which digital representations of music are stored and transferred electronically in a network as files, is increasingly popular. Various peer to peer file sharing programs have hastened the popularity of online music, as have the proliferation of computing devices that can store and “play” such digital representations of music. Web sites or other programs have now begun to emerge by which consumers can browse, listen, and purchase music, usually in the form of an online “store” that mail ordered CDs to the customer.
Conventional online music purchasing systems do not offer a radio service, in which digital media files such as music are transmitted an received for playing in near real time. Likewise, typical online radio services do not allow a user to select and purchase a song that has previously played or is currently playing. The user usually cannot employ the radio functionality at the same time he or she is purchasing a track.
Some conventional digital rights management (DRM) schemes do not support the concept of set-wise rights, i.e. rights pertaining to playlists of multiple tracks. Additionally, some of these implementations of DRM do not allow tracks that are licensed to be utilized on multiple machines (e.g. a work machine, a home machine, and a laptop). There might also be a lack of provisions to protect and treat a playlist of multiple tracks as an entity. However, current DRM schemes require that the content be encrypted, and that keys used for decrypting the content be stored securely. This can make accessing DRM compliant content computationally and time intensive, and can further result in sluggish behavior from applications that access DRM content.